[Reflection.Assembly]::LoadWithPartialName("PresentationCore") | Out-Null

$path = "C:\"

$date = Get-Date "1/1/2014 9:00 AM"
$fps = 30

foreach ($path in (Get-ChildItem $path -Filter "*.jpg").FullName)
{
    $stream = [System.IO.File]::Open($path, "Open")

    $bitmapDecoder = [System.Windows.Media.Imaging.BitmapDecoder]::Create($stream, "None", "Default")

    $metadataWriter = $bitmapDecoder.Frames[0].CreateInPlaceBitmapMetadataWriter()

    $metadataWriter.DateTaken = $date

    Write-Host "Writing ${path}: $date"

    if (-not $metadataWriter.TrySave())
    {
        Write-Error "Error writing metadata to $path."
    }

    $date = $date.AddSeconds(1 / $fps)

    $stream.Close()
}